/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.rule;

import org.dom4j.Node;

/**
 * <p> <code>Rule</code> matches against DOM4J Node so that some action can be
 * performed such as in the XSLT processing model. </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public class Rule implements Comparable
{
   /** Holds value of property mode. */
   private String mode;

   /** Holds value of property importPrecedence. */
   private int importPrecedence;

   /** Holds value of property priority. */
   private double priority;

   /** Holds value of property appearenceCount. */
   private int appearenceCount;

   /** Holds value of property pattern. */
   private Pattern pattern;

   /** Holds value of property action. */
   private Action action;

   public Rule()
   {
      this.priority = Pattern.DEFAULT_PRIORITY;
   }

   public Rule(Pattern pattern)
   {
      this.pattern = pattern;
      this.priority = pattern.getPriority();
   }

   public Rule(Pattern pattern, Action action)
   {
      this(pattern);
      this.action = action;
   }

   /**
    * Constructs a new Rule with the same instance data as the given rule but a
    * different pattern.
    * 
    * @param that DOCUMENT ME!
    * @param pattern DOCUMENT ME!
    */
   public Rule(Rule that, Pattern pattern)
   {
      this.mode = that.mode;
      this.importPrecedence = that.importPrecedence;
      this.priority = that.priority;
      this.appearenceCount = that.appearenceCount;
      this.action = that.action;
      this.pattern = pattern;
   }

   public boolean equals(Object that)
   {
      if(that instanceof Rule)
      {
         return compareTo((Rule) that) == 0;
      }

      return false;
   }

   public int hashCode()
   {
      return importPrecedence + appearenceCount;
   }

   public int compareTo(Object that)
   {
      if(that instanceof Rule)
      {
         return compareTo((Rule) that);
      }

      return getClass().getName().compareTo(that.getClass().getName());
   }

   /**
    * Compares two rules in XSLT processing model order assuming that the modes
    * are equal.
    * 
    * @param that DOCUMENT ME!
    * 
    * @return DOCUMENT ME!
    */
   public int compareTo(Rule that)
   {
      int answer = this.importPrecedence - that.importPrecedence;

      if(answer == 0)
      {
         answer = (int) Math.round(this.priority - that.priority);

         if(answer == 0)
         {
            answer = this.appearenceCount - that.appearenceCount;
         }
      }

      return answer;
   }

   public String toString()
   {
      return super.toString() + "[ pattern: " + getPattern() + " action: "
         + getAction() + " ]";
   }

   /**
    * DOCUMENT ME!
    * 
    * @param node DOCUMENT ME!
    * 
    * @return true if the pattern matches the given DOM4J node.
    */
   public final boolean matches(Node node)
   {
      return pattern.matches(node);
   }

   /**
    * If this rule contains a union pattern then this method should return an
    * array of Rules which describe the union rule, which should contain more
    * than one rule. Otherwise this method should return null.
    * 
    * @return an array of the rules which make up this union rule or null if
    *         this rule is not a union rule
    */
   public Rule[] getUnionRules()
   {
      Pattern[] patterns = pattern.getUnionPatterns();

      if(patterns == null)
      {
         return null;
      }

      int size = patterns.length;
      Rule[] answer = new Rule[size];

      for(int i = 0; i < size; i++)
      {
         answer[i] = new Rule(this, patterns[i]);
      }

      return answer;
   }

   /**
    * DOCUMENT ME!
    * 
    * @return the type of node the pattern matches which by default should
    *         return ANY_NODE if it can match any kind of node.
    */
   public final short getMatchType()
   {
      return pattern.getMatchType();
   }

   /**
    * For patterns which only match an ATTRIBUTE_NODE or an ELEMENT_NODE then
    * this pattern may return the name of the element or attribute it matches.
    * This allows a more efficient rule matching algorithm to be performed,
    * rather than a brute force approach of evaluating every pattern for a given
    * Node.
    * 
    * @return the name of the element or attribute this pattern matches or null
    *         if this pattern matches any or more than one name.
    */
   public final String getMatchesNodeName()
   {
      return pattern.getMatchesNodeName();
   }

   /**
    * Getter for property mode.
    * 
    * @return Value of property mode.
    */
   public String getMode()
   {
      return mode;
   }

   /**
    * Setter for property mode.
    * 
    * @param mode New value of property mode.
    */
   public void setMode(String mode)
   {
      this.mode = mode;
   }

   /**
    * Getter for property importPrecedence.
    * 
    * @return Value of property importPrecedence.
    */
   public int getImportPrecedence()
   {
      return importPrecedence;
   }

   /**
    * Setter for property importPrecedence.
    * 
    * @param importPrecedence New value of property importPrecedence.
    */
   public void setImportPrecedence(int importPrecedence)
   {
      this.importPrecedence = importPrecedence;
   }

   /**
    * Getter for property priority.
    * 
    * @return Value of property priority.
    */
   public double getPriority()
   {
      return priority;
   }

   /**
    * Setter for property priority.
    * 
    * @param priority New value of property priority.
    */
   public void setPriority(double priority)
   {
      this.priority = priority;
   }

   /**
    * Getter for property appearenceCount.
    * 
    * @return Value of property appearenceCount.
    */
   public int getAppearenceCount()
   {
      return appearenceCount;
   }

   /**
    * Setter for property appearenceCount.
    * 
    * @param appearenceCount New value of property appearenceCount.
    */
   public void setAppearenceCount(int appearenceCount)
   {
      this.appearenceCount = appearenceCount;
   }

   /**
    * Getter for property pattern.
    * 
    * @return Value of property pattern.
    */
   public Pattern getPattern()
   {
      return pattern;
   }

   /**
    * Setter for property pattern.
    * 
    * @param pattern New value of property pattern.
    */
   public void setPattern(Pattern pattern)
   {
      this.pattern = pattern;
   }

   /**
    * Getter for property action.
    * 
    * @return Value of property action.
    */
   public Action getAction()
   {
      return action;
   }

   /**
    * Setter for property action.
    * 
    * @param action New value of property action.
    */
   public void setAction(Action action)
   {
      this.action = action;
   }
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
